The overal goals of this project are to characterize fully the process of herpes simplex virus messenger RNA biogenesis and its regulation in productively infected human cells. Sepcifically these studies include a) identification and characterization of viral transcription units and mRNAs according to polypeptide encoding, genome mapping, and regulation of expression and b) elucidation of the transcriptional controls operative in viral gene expression. In the coming year we plan to 1) characterize the in vivo transcription of selected, cloned regions of the HSV-1 genome using hybridization selection of viral mRNAs, in vitro translation of viral mRNAs, and genome mapping by biochemical and physical techniques, 2) correlate the in vivo transcription pattern from selected viral DNA regions with the in vitro transcription pattern using an RNA polymerase II system recently developed in this laboratory, 3) to study the controls of viral gene transcription using RNA polymerase II preparations and factors from uninfected and infected cells, and selected, cloned, HSV-1 DNA fragemnts, as templates.